銅銦鎵硒薄膜太陽能電池具備可撓且高光伏特性的潛能，已經吸引眾多的關注，於此，合金後硒化是最具商業化過程，但是在純硒化過程中，容易產生鎵在背電極處累積的問題，導致嚴重的相分離以及陡峭的鎵梯度，並且元件的理想因子不佳，進而降低了元件的轉換效率。本論文著眼於此，致力改善純硒化過程中所衍生出的問題，並藉以提高元件表現效率，我們分為三個部分來解決這些問題:

第一部分，我們提出一種有效的硒化方法，利用爐管內背景壓力的調控，進而影響硒氣氛的分壓並製造出合適的鎵梯度，研究結果發現，增加爐管背景壓力從真空到一大氣壓，能夠有效使得鎵往前移，並且得到高薄膜品質的CIGS，平均效率可提升10%以上，此部分研究詳細探討爐管背景壓力對薄膜生長的行為之影響。

第二部分，由於在背景壓力一大氣壓下可得高品質的CIGS，但是此過高的硒分壓會導致在背電極處會產生一層超過1.5 um的MoSe2，增加元件的串聯電阻，進而降低元件的填充因子。我們提出將擴散阻擋層TiN 的引入，有效隔絕硒與鉬的反應，並成功將MoSe2 減薄至100 nm左右。

第三部分，當引入擴散阻擋層不僅僅能夠阻擋硒分壓，然而也會抑制鈉玻璃基板來的鈉原子，我們提出一個合適的前驅層疊層設計，以彌補鈉的缺少，藉此促進元件表現效率，最後我們成功得到超過16%的元件表現效率，就我們所知，這是報導中不靠外加硫只單純硒化的CIGS世界級效率。

CIGSe solar cell is a promising material due to their flexibility and potential to high photovoltaic properties. It has attracted lots of attention. Post annealing of precursors under chalcogen atmosphere is one of the most commertialize method to fabricate the CIGSe. However, Ga commonly segregates at the back contact during the post selenization process, which is the serious problem of phase separation. It deteriorates the fill factor and further degenerates the solar cells performance. We point out the approach to ameliorate the situation during the pure selenization and its derivate issue. We separate into three parts to solve these problems.

In the first part, we propose an effective way for the pure selenization by modifying the background pressure to influence the Se partial pressure and further engineering the proper Ga grading profile. With the enhancement of the background pressure from vacuum to one atmosphere, Gallium tends to move toward and acquisition of the high quality CIGSe films with over 10% efficiency enhancement. In this part, we focus on the relationship between the background pressure and the properties of the films.

In the second part, high quality CIGSe films are fabricated by high selenium partial pressure. However, there are over 1.5 um MoSe2 remains to increase the series resistance and further reduce the fill factor. We propose an approach to isolate the reaction between Selenium and Moly, in terms of introduce the ultrathin TiN diffusion barrier. MoSe2 can be reduced from over 1.5um to only 100 nm successfully.

In the third part, a TiN diffusion barrier not only to reduce the thickness of MoSe2 but also to restrict the Sodium out-diffuse from the soda lime glass(SLG) substrate. We also propose a suitable precursor architecture to improve the solar cell devices by reducing of Sodium deficit. Finally, we successfully obtain the device performance with over 16.0% efficiency. To our understanding, it is the highest CIGSe solar cell device via post-annealing treatments without any sulfur incorporation.

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